Field of the Invention
The present invention relates to an electronically controlled internal damper, and more particularly, to an electronically controlled internal damper that is capable of implementing damping performance in both a soft mode and a hard mode through a relatively simple structure and increasing sealing performance while reducing rigidity.
Description of the Related Art
Generally, in an electronically controlled external damper, since a passage of a rebound stroke is the same as a passage of a compression stroke, damping forces of the rebound stroke and the compression stroke is adjusted through one variable valve.
Consequently, the electronically controlled external damper cannot independently adjust the damping forces of the rebound stroke and the compression stroke in the valve, wherein a difference in the damping force occurs depending on the difference in a flow rate passing through the same valve.
In consideration of these points, it is possible to adjust the damping force of the compression stroke through a rigidity of a check valve on a compression side of a main piston, but its degree of freedom is considerably limited as compared with a conventional damper that adjusts a damping force by using a separate valve in each stroke.
Therefore, even though the electronically controlled damper is expensive as compared with the conventional damper, the degree of freedom of damping force adjustment decreases.
On the other hand, the electronically controlled internal damper can independently control the damping forces through the separate independent valves in the rebound stroke and the compression stroke as in the conventional damper. However, in order to increase the flow rate on the compression side of the variable valve and implement damping performance in a hard mode, the stacking number of disks for sealing increases and thus the rigidity increases.
If the rigidity on the compression side of the variable valve increases, a damping force of a soft mode increases and thus the degree of freedom of damping force adjustment decreases.